Nuffield Trust warned that the care sector could be left with a staff shortage of 70,000.

The UK could be forced to spend an extra £500m a year to meet the health costs of tens of thousands pensioners returning from other EU countries after Brexit, a top think-tank claimed on Wednesday (31 May).

The Nuffield Trust explained that the 190,000 British pensioners living on the continent receive healthcare under the EU's reciprocal "S1" scheme.

But if the initiative is withdrawn and expats return to the UK, the annual cost to the NHS would be around £979m (€1.12bn).

Since Britain currently puts £500m a year into the S1 scheme, the extra cost would be around £500m

"The NHS and social care were already under pressure from tight funding settlements and growing staffing problems well before the EU referendum last year," said Mark Dayan, Nuffield Trust policy and public affairs analyst.

"But if we handle it badly, leaving the EU could make these problems even worse, given the potential impact on both the strength of the UK economy and the supply of overseas staff to both health and social care services.

"It is possible that extra funds could be found for the NHS from any cancellation of Britain's EU membership fees – but whether or not these benefits will outweigh the significant staffing and financial costs Brexit may impose on already stretched services remains to be seen.

"That depends largely on the NHS being recognised as a significant priority as we enter some of the most important negotiations in Britain's history".